CSCI 3328 Object Oriented Programming in C# Chapter 10: Graphical User Interfaces with Windows Forms 1 Xiang Lian The University of Texas – Pan American Edinburg, TX

Objectives In this chapter, you will –Learn how to process events that are generated by user interface controls and event handling –Know how to create and use Button, Label, RadioButton, CheckBox, TextBox, Panel and NumbericUpDown controls –Know how to add ToolTips to GUI controls –Discover how to process mouse and keyboard events –Become familiar with more controls, such as Menus, tabbed windows, and multiple document interface (MDI), ListView, TreeView, LinkLabel, ListBox, ComboBox, DateTimePicker 2

Windows Forms Dialog MDI (window multiple document Interface) Window Controls and components are placed on the form Toolbox allows you to choose controls and components A form is a container that holds the controls and components 3

Controls 4

Event Handling Events drive the program to perform a task –Click –Change –Time Event handler is what you write 5

Example of Event-Driven GUI Click event of Button private void clickButton_Click(object sender, EventArgs e) { MessageBox.Show("Button was clicked"); } 6

Visual Studio Generated Code Can give great insight into what is going on See what is in the Designer.cs –It will have all controls and components you placed there 7

Integrated Development Environment Events Properties window events 8

Creating Event Handlers Double click on a control and write code –Known as default event You can use the properties window to create event handlers Click on the events (looks like the lightning) in the properties window 9

Control Properties and Layout Controls derive from class Control Common control properties –BackColor –BackgroundImage –Enabled –Focused –Font –ForeColor –TabIndex –Text –Visible Common methods –Hide –Select –Show 10

Anchor Property Anchoring causes controls to remain at a fixed distance from the sides of the container, even when the container is resized –Darkened bar indicate the container’s sides to which the control is anchored 11

Dock Property and Other Properties 12 Dock Other properties –Location –Size –MaximumSize –MinimumSize

Labels, TextBoxes and Buttons A Label displays text that the user cannot directly modify A TextBox is an area in which either text can be displayed by a program or user can type text via keyboard –A password TextBox Set UseSystemPasswordChar to true A Button is a control that the user clicks to trigger a specific action or to select an option in a program 13

Common Properties/Events of Labels, TextBoxes and Buttons Label –Font, Text, TextAlign TextBox –AcceptReturn If true in a multiline TextBox, pressing Enter in the TextBox creates a new line –Multiline, ReadOnly, ScrollBars, Text, UseSystemPasswordChar –Event: TextChanged Button –Text, FlatStyle –Event: Click 14

GroupBoxes and Panels GroupBoxes and Panels arrange controls on a GUI All controls in a GroupBox or Panel move together when the GroupBox or Panel is moved Properties of GroupBoxes –Controls –Text Properties of Panels –AutoScroll (when resizing panels) –BorderStyle –Controls 15

CheckBoxes and RadioButtons CheckBoxes –Appearance, Checked, CheckState, Text –ThreeState Checked, unchecked, and indeterminate (grey color; can be set programmatically) –Event: CheckedChanged, CheckStateChanged RadioButtons –Checked, Text –Event: CheckedChanged 16

Example of CheckBoxes and RadioButtons private void boldCheckBox_CheckedChanged(object sender, EventArgs e) { outputLabel.Font = new Font(outputLabel.Font, outputLabel.Font.Style ^FontStyle.Bold); } private MessageBoxButtons buttonType; private void buttonType_CheckedChanged(object sender, EventArgs e) { if (sender == okRadioButton) buttonType = MessageBoxButtons.OK; } 17 name of a radio button

PictureBox Properties –Image –SizeMode Events –Click Example of setting image resources –imagePictureBox.Image=(Image) (Properties.Resources.ResourceManager.GetObject("image1"); 18

ToolTips Drag ToolTip to the form –Then each control has a new property "ToolTip on toolTip1" Properties –AutoPopDelay The amount of time that the tool tip appears while the mouse is over a control –InitialDelay The amount of time that a mouse must hover over a control before a tool tip appears –ReshowDelay: The amount of time between which two different tool tips appear Load Method of the form –tooltip1.SetToolTip(this.button1, "tips here"); Event –Draw 19

NumericUpDown Control Properties –DecimalPlaces –Increment –Maximum –Minmum –UpDownAlign –Value Event –ValueChanged 20

Mouse Handling private void PainterForm_MouseDown(object sender, MouseEventArgs e) { shouldPaint = true; } private void PainterForm_MouseUp(object sender, MouseEventArgs e) { shouldPaint = false; } private void PainterForm_MouseMove(object sender, MouseEventArgs e) { if (shouldPaint) { Graphics graphics = CreateGraphics(); graphics.FillEllipse(new SolidBrush(Color.BlueViolet), e.X, e.Y, 4, 4); graphics.Dispose();//dispose of resources } 21 Location of the mouse

Mouse Handling (cont'd) Event EventArgs –MouseEnter –MouseLeave Event MouseEventArgs –MouseDown –MouseHover –MouseMove –MouseUp Properties of class MouseEventArgs –Button (Left, Right, Middle or none button of the mouse) –Clicks (number of clicking times) –X –Y 22

Keyboard Events Event KeyEventArgs –KeyDown –KeyUp Event KeyPressEventArgs –KeyPress Properties of class KeyPressEventArgs –KeyChar –Handled (whether the event was handled) Properties of class KeyEventArgs –Alt (whether Alt key was pressed) –Control (whether Ctrl key was pressed) –Shift (whether Shift key was pressed) –Handled (whether the event was handled) 23

Menus Main menu bar –Type menu name –Place & character before a letter to underline it E.g., &File Effect: File (you can press Alt+F keys to select file menu) –Select shortcut keys for menu items –You can remove a menu item by selecting it with mouse and pressing Delete key 24

Menus (cont'd) Options of menu items –Right click a menu item –ToolStripMenuItem –ComboBox –Separator –TextBox 25

Menus (cont'd) MenuStrip Properties –HasChildren –RightToLeft ToolStripMenuItem Properties –Checked –CheckOnClick –Index –MenuItems ToolStripMenuItem Event –Click 26

Example of Menus Checked Property –blackToolStripMenuItem.Checked = true; Event private void blackToolStripMenuItem_Click(object sender, EventArgs e) { displayLabel.ForeColor = Color.Black; blackToolStripMenuItem.Checked = true; } 27

MonthCalendar Control Properties –FirstDayOfWeek –MaxDate –MaxSelectionCount Maxixmum number of dates that can be selected at once –MinDate –MonthlyBoldedDates An array of dates that will be displayed in bold in the calendar –SelectionEnd –SelectionRange –SelectionStart Event –DateChanged 28

DateTimePicker Control Properties –CalendarForeColor –CalendarMonthBackground –CustomFormat –Date –Format –MaxDate –MinDate –ShowCheckBox –ShowUpDown –TimeOfDay –Value Event –ValueChanged 29

Example of DateTimePicker private void dateTimePickerDropOff_ValueChanged(object sender, EventArgs e) { DateTime dropOffDate = dateTimePickerDropOff.Value; if (dropOffDate.DayOfWeek == DayOfWeek.Friday || dropOffDate.DayOfWeek == DayOfWeek.Saturday || dropOffDate.DayOfWeek == DayOfWeek.Sunday) outputLabel.Text = dropOffDate.Add(3).ToLongDateString(); else outputLabel.Text = dropOffDate.Add(2).ToLongDateString(); } 30

LinkLabel Control Properties –LinkVisited If true, the link appears as though it has been visited –LinkColor –Text –VisitedLinkColor Event –LinkClicked System.Diagnostics.Process.Start(" System.Diagnostics.Process.Start("notepad"); 31

ListBox Control Properties of ListBox –SelectionMode –MultiColumn –SelectedIndex If no items are selected, SelectedIndex = 1 –SelectedIndices For multiple selected items –SelectedItem –SelectedItems –Sorted Indicate whether items are sorted alphabetically Methods of ListBox –ClearSelected –GetSelected(index) Return true, if the corresponding item is selected Event of List Box –SelectedIndexChanged 32

Example of ListBox Control myListBox.Items.Add(myListItem); CheckedListBox Control –Inherit from ListBox 33

ComboBox Control Properties –DropDownStyle –Items –MaxDropDownItems –SelectedIndex –SelectedItem –Sorted Event –SelectedIndexChanged 34

Other Controls TreeView Control –"Nodes" property Add root, or add child –AfterSelect event When selected node changes 35

Other Controls (cont'd) TabControl Control –Contains TabPage objects which are similar to Panels and GroupBoxes –myTabPage.Controls.Add(myControl); –myTabPage.Controls.Add(myTabPage); Properties –ImageList –ItemSize Tab size –Multiline –SelectedIndex –SelectedTab –TabCount –TabPages Add more tabs Event –SelectedIndexChanged 36

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